Global Setting – September 2013

The equatorial Pacific Ocean continues in a neutral state (neither El Niño nor La Niña), with recent cooler-than-normal sea-surface conditions (La Niña-like) in the eastern tropical Pacific having weakened. International guidance indicates that ENSO-neutral conditions are the most likely outcome for the next three months (October–December). In the New Zealand region, higher pressures than normal are forecast to south of the country and lower pressures than normal are forecast in the Australian Bight extending eastwards into the central Tasman. This circulation pattern is expected to produce northerly quarter flows over the north of the country, and a slightly enhanced easterly flow over the lower South Island.

Sea Surface Temperature 

Sea surface temperatures are expected to remain above average overall around New Zealand 

 

Note: no NOAA map is available at present, due to the US Federal government shutdown having suspended NOAA.gov and most associated web sites. 

Monthly values of the Southern Oscillation Index (SOI), a measure of changes in atmospheric pressures across the Pacific, and the 3-month mean (black line). SOI mean values: September SOI +0.3; July to September average +0.3.